Metal-cutting tool



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1,629,667 y 1927- J, D. KNIPPLE METAL CUTTING TOOL Filed Oct. 15, 1926Inventor:

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ag MM 64% War/MK Patented May 24, 1927,.

UNITED ,STATES PATENT OFFICE METAL-CUTTING roon.

Application filed October 15, 1926. Serial No. 141,751. g

This invention relates to metal cutting tools and while not limitedthereto, relates more particularly to tools for use in heavy dutyplaners such as are used in planing railway frogs, crossovers and otherheavy steel structures.

In the commercial production of railway track structures such as frogs,crossovers, and the like, it is necessary to form certain parts byplaning operations and, in order to reduce the cost of these operationsto a minimum, heavy duty planing machines have been develo ed capab e ofmaking deep cuts by using a igh grade of special highspeed tool steeltools.

Heretofore the high-speed tool steel tools for use in these machineshave consisted of a standard steel holder with a high-speed tool steelcutter or bit welded thereto, and when the cutting edge of the cutter orbit was worn down, due to continual sharpening, the entire tool had tobe discarded, resulting in the loss of the tool-holder and the.remaining portion of the high-speed tool steel bit.

The present invention provides a tool composed of a tool or bit holderhaving a delnountable high-speed tool steel cutter or' bit which may bereplaced when worn, and the worn bit may be reused in tools havingshorter heads, thereby entirely reducing the loss resulting fromdiscarding the tool-holders and materially reducing the loss resultingfrom the discarding of .the worn bits or cutters.

In the drawings- Figure 1 is a side elevation of a tool constructed inaccordance with this invention.

' Figure 2 is a plan view of the bit supporting head of the tool holder.

Figure 3 is a similar view with the tool bit removed.

Figure 4 is a perspective View of the tool bit.

Figure 5 is a perspective view of the head end of the tool holder.

Referring more articularly to the drawings, the letter A esignates thetool-holder as a whole, which supports a cutter-or bit B.

The tool-holder A comprises a squared shank portion 2 terminating at itslower end in an enlarged bit supporting head 3. The head 3 has itsforward face recessed from its lower end upwardly and inwardly forming acutter or bit seat 4. The rear wall of the seat 4 is provided with aslot 5 extendin axis 0 the tool and the top wal of said seat is undercuttoprovide an overhanging beveled retaining flange 6.-

The high-speed tool steel bit B is mounted in the seat 4 and comprises abod ortion 7 having its upper end face beve e as at 8, so as to PI'OJQCtand engage underthe retaining flan 'e 6. The rear face of the bit B isprovided with a, transversely extending supporting rib 9 adapted toextend into the slot 5, and serves to prevent twisting of the bit underheavy duty. The lower end of the bit B is cut away to form a pr jectingcutting nose 10, and the lower end of the head 3 of the holder A isprovided with a centrally disposed rib 12 adapted to engage the bit andreinforce and support the nose 10.

A bolt 13 is passed through the head 3 and the bit B and provided with,a nut 14 for locking the bit B in position and preventing displacement.thereof.

In use the bits B may be sharpened by grinding without removing themfrom the holders A, as is usual until their cutting edges are cut downtoo close to'the holders. After the bits B have their cuttin edgesground down too close to the hol ers A, the bits are removed and newbits substituted therefor. i

The bits removed from the holders as above described, may then be fittedto new holders having shorter heads 3 so as to again expose theircutting edges and permit their use, or such bits maybe mounted inlighter and smaller tool holders for use in other machines as desired,so that the maximum amount of the high-speed tool steel bits may beutilized before they need be discarded.

at right angles to the lon itudinal While I have shown and described onespecific embodiment of my invention, it will be understood that I do notwish to be limited thereto since various modifications may be madewithout departing from the scope of my invention as defined in theappended claims.

I claim- 1. A tool of the class described, comprising a shank, anenlarged cutter supporting head formed integral with the. lower end ofsaid shank, said head having its forward face recessed from its lowerend upwardly and inwardly to form a cutter, bitsea't, the rear wall ofsaid seat being provided with a slot extending at right angles to thelongitudinal axis of the tool and the top wall of said seat beingundercut to provide an overhanging retaining flange, and a high-speedtool steel cutter bit mounted in, said cutter seat, said bit having itsupper end beveled so as to project andengage under said retainingflange, a supporting rib projecting from the rear face of said bit andengaged in said slot in the rear wall of said seat, and means forlocking said bit against displacement relative to said seat.

2. A tool of the class described, comprising a shank, an enlarged cuttersupporting head formed integral with the lower end of said shank, saidhead having its forward face recessed from its lower end upwardly andinwardly to form a cutter bit seat, the rear wall of said seat beingprovided with a slot extending at right angles to the longitudinal axisof the tool and the top wall of said seat being undercut to provide anoverhanging retainin flange, and a high-speed tool steel cutter itmounted in said cutter seat, said bit havin its upper end beveled so asto roject and engage under said retaining ange and its lower end cut awato form a cutting nose, a supporting ri projecting from the rear face ofsaid bit andengaged in said slot in the rear wall of said seat, a boltpassing through said cutter supporting head and saidbit to lock said bitagainst displacement, and means formed integral with the lower end ofsaid head for supporting said cutting nose.

In testimony whereof, I have hereunto signed my name.

JAMES D. KNIPPLE.

